Optical proximity sensors

ABSTRACT

A proximity sensor, including a housing, an array of lenses mounted in the housing, an array of alternating light emitters and light detectors mounted in the housing, each detector being positioned along the image plane of a respective one of the lenses so as to receive maximum light intensity when light enters the lens at a particular angle, an activating unit mounted in the housing and connected to the emitters and detectors, synchronously co-activating each emitter with at least one of the detectors, each activated emitter projecting light out of the housing along a detection plane, and a processor receiving outputs from the detectors corresponding to amounts of projected light reflected by an object in the detection plane to the detectors, and calculating a two-dimensional location of the object in the detection plane based on the detector outputs and the particular angle.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/312,787, now U.S. Pat. No. 9,164,625, entitled OPTICAL PROXIMITYSENSORS, and filed on Jun. 24, 2014 by inventors Stefan Holmgren, SairamIyer, Richard Berglind, Karl Erik Patrik Nordstrom, Lars Sparf, PerRosengren, Erik Rosengren, John Karlsson, Thomas Eriksson, AlexanderJubner, Remo Behdasht, Simon Fellin, Robin Aman and Joseph Shain. U.S.application Ser. No. 14/312,787 is a continuation of PCT Application No.PCT/US14/40112, entitled OPTICAL PROXIMITY SENSORS, and filed on May 30,2014 by inventors Stefan Holmgren, Sairam Iyer, Richard Berglind, KarlErik Patrik Nordstrom, Lars Sparf, Per Rosengren, Erik Rosengren, JohnKarlsson, Thomas Eriksson, Alexander Jubner, Remo Behdasht, SimonFellin, Robin Åman and Joseph Shain.

PCT Application No. PCT/US14/40112 claims priority benefit from:

-   -   U.S. Provisional Patent Application No. 61/828,713, entitled        OPTICAL TOUCH SCREEN SYSTEMS USING REFLECTED LIGHT, and filed on        May 30, 2013 by inventors Per Rosengren, Lars Sparf, Erik        Rosengren and Thomas Eriksson;    -   U.S. Provisional Patent Application No. 61/838,296, entitled        OPTICAL GAME ACCESSORIES USING REFLECTED LIGHT, and filed on        Jun. 23, 2013 by inventors Per Rosengren, Lars Sparf, Erik        Rosengren, Thomas Eriksson, Joseph Shain, Stefan Holmgren, John        Karlsson and Remo Behdasht;    -   U.S. Provisional Patent Application No. 61/846,089, entitled        PROXIMITY SENSOR FOR LAPTOP COMPUTER AND ASSOCIATED USER        INTERFACE, and filed on Jul. 15, 2013 by inventors Richard        Berglind, Thomas Eriksson, Simon Fellin, Per Rosengren, Lars        Sparf, Erik Rosengren, Joseph Shain, Stefan Holmgren, John        Karlsson and Remo Behdasht;    -   U.S. Provisional Patent Application No. 61/929,992, entitled        CLOUD GAMING USER INTERFACE, and filed on Jan. 22, 2014 by        inventors Thomas Eriksson, Stefan Holmgren, John Karlsson, Remo        Behdasht, Erik Rosengren, Lars Sparf and Alexander Jubner;    -   U.S. Provisional Patent Application No. 61/972,435, entitled        OPTICAL TOUCH SCREEN SYSTEMS, and filed on Mar. 30, 2014 by        inventors Sairam Iyer, Karl Erik Patrik Nordstrom, Per        Rosengren, Stefan Holmgren, Erik Rosengren, Robert Pettersson,        Lars Sparf and Thomas Eriksson;    -   U.S. Provisional Patent Application No. 61/986,341, entitled        OPTICAL TOUCH SCREEN SYSTEMS, and filed on Apr. 30, 2014 by        inventors Sairam Iyer, Karl Erik Patrik Nordstrom, Lars Sparf,        Per Rosengren, Erik Rosengren, Thomas Eriksson, Alexander Jubner        and Joseph Shain; and    -   U.S. patent application Ser. No. 14/140,635, now U.S. Pat. No.        9,001,087, entitled LIGHT-BASED PROXIMITY DETECTION SYSTEM AND        USER INTERFACE, and filed on Dec. 26, 2013 by inventors Thomas        Eriksson and Stefan Holmgren.

U.S. patent application Ser. No. 14/140,635 is a continuation-in-part ofU.S. patent application Ser. No. 13/732,456, now U.S. Pat. No.8,643,628, entitled LIGHT-BASED PROXIMITY DETECTION SYSTEM AND USERINTERFACE, and filed on Jan. 2, 2013 by inventors Thomas Eriksson andStefan Holmgren. U.S. patent application Ser. No. 13/732,345 claimspriority benefit from U.S. Provisional Patent Application No.61/713,546, entitled LIGHT-BASED PROXIMITY DETECTION SYSTEM AND USERINTERFACE, and filed on Oct. 14, 2012 by inventor Stefan Holmgren.

U.S. application Ser. No. 14/312,787, is a continuation-in-part of U.S.patent application Ser. No. 13/775,269, now U.S. Pat. No. 8,917,239,entitled REMOVABLE PRETECTIVE COVER WITH EMBEDDED PROXIMITY SENSORS, andfiled on Feb. 25, 2013 by inventors Thomas Eriksson, Stefan Holmgren,John Karlsson, Remo Behdasht, Erik Rosengren and Lars Sparf.

The contents of all of these applications are hereby incorporated byreference in their entireties.

FIELD OF THE INVENTION

The field of the present invention is light-based touch screens.

BACKGROUND OF THE INVENTION

Many consumer electronic devices are now being built with touchsensitive screens, for use with finger or stylus touch user inputs.These devices range from small screen devices such as mobile phones andcar entertainment systems, to mid-size screen devices such as notebookcomputers, to large screen devices such as check-in stations atairports.

The present invention relates to light-based touch screens. Prior artlight-based touch screens surround the screen borders with lightemitters and light detectors to create a light beam grid above thescreen surface. An object touching the screen from above blocks acorresponding portion of the beams.

Reference is made to FIG. 1, which is a diagram of a prior art,light-based touch screen having 16 LEDs and 16 PDs. Screen 100 in FIG. 1is surrounded by emitters 130 along two edges and photodiode (PD)receivers 240 along the remaining two edges, which together enable alattice of light beams covering the screen.

One drawback of prior art light-based touch screens is the need toaccommodate the numerous light emitters and light detectors along allfour edges of the screen. This requirement makes it difficult to insertlight-based touch detection into an existing electronic device withoutsignificantly changing the layout of the device's internal components.It would be advantageous to reduce the number of components required andto enable placing them in a limited area rather than surrounding theentire screen. Reducing the total number of light emitters and lightdetectors required has the added benefit of reducing thebill-of-materials (BOM).

SUMMARY

Embodiments of the present invention provide two-dimensional (2D) touchdetection using a one-dimensional array of alternating light emittersand detectors. Other embodiments of the present invention provide 2Dtouch detection using a one-dimensional array of light emitters alongonly one edge of the screen and an opposite array of light detectorsalong the opposite edge of the screen. The present invention alsoprovides a three-dimensional (3D) touch or hover detector based on thesame principles as the 2D detectors.

There is thus provided in accordance with an embodiment of the presentinvention a row of alternating light emitters and detectors. The lightemitters project collimated light beams perpendicular to the row andparallel to each other in sequence. The light detectors detect lightfrom the emitters that has been reflected by an object inserted into thelight beam path. Each detector detects light in the plane of the emitterbeams, but at a fixed angle relative to those beams. The distancebetween an emitter and a detector that detects light reflected from theemitter's beam, together with the fixed angle, is used to determine thelocation of the reflecting object by triangulation.

There is additionally provided in accordance with an embodiment of thepresent invention a row of light emitters along the bottom edge of thescreen and a row of light detectors along the top edge of the screen.Each light emitter projects a very wide beam that is detected by all ofthe light detectors. The x-coordinate of an object touching the screencorresponds to a blocked beam that runs parallel to the side edges ofthe screen. The y-coordinate is determined by identifying theintersections between diagonal blocked beams.

There is further provided in accordance with an embodiment of thepresent invention a proximity sensor for determining two-dimensionalcoordinates of a proximal object, including a housing, a plurality oflight pulse emitters mounted in the housing for projecting light out ofthe housing along a detection plane, a plurality of primary lightdetectors mounted in the housing for detecting reflections of the lightprojected by the emitters, by a reflective object in the detectionplane, a plurality of primary lenses mounted and oriented in the housingrelative to the emitters and the primary detectors in such a manner thatfor each emitter-detector pair, light emitted by the emitter of thatpair passes through one of the primary lenses and is reflected by theobject back through one of the primary lenses to the detector of thatpair when the object is located at a two-dimensional position, fromamong a primary set of positions in the detection plane, that positionbeing associated with that emitter-detector pair, and a processorconnected to the emitters and to the primary detectors, forsynchronously co-activating emitter-detector pairs, and configured tocalculate a two-dimensional location of the object in the detectionplane by determining an emitter-detector pair among the co-activatedemitter-detector pairs, for which the detector detects a maximum amountof light, and identifying the position associated therewith, determiningadditional positions that are associated with co-activatedemitter-detector pairs and that neighbor the thus-identified position,and calculating a weighted average of the thus-identified position andthe thus-determined additional positions, wherein each position's weightin the average corresponds to a degree of detection of the reflectedlight beam for the emitter-detector pair to which that position isassociated.

There is yet further provided in accordance with an embodiment of thepresent invention a proximity sensor for determining directionalmovement of a finger along a slider control, including a housing, amulti-layer, light transmissive cover mounted in said housing and havingan exposed upper surface for a slider control, wherein a border betweenthe layers of the cover comprises a pattern of light-transmissiveportions separated by opaque or reflective portions, wherein the sizesof the light-transmissive portions, or of the opaque or reflectiveportions, increase across the pattern, a light pulse emitter mounted inthe housing for projecting light into an upper layer of the cover, theprojected light being confined to the upper layer by total internalreflection (TIR), wherein a finger touching the exposed upper surfacefrustrates the TIR light, causing a portion of the light to enter asecond layer, underneath the upper layer and separated therefrom by thepattern, through the light-transmissive portions in the pattern, theportion of light entering the second layer corresponding to the sizes ofthe light-transmissive portions beneath the finger touching the exposedupper surface, a light detector mounted in the housing for detectingintensities of light in the second layer, and a processor connected tothe light detector for determining directional movement of the objectacross the pattern, wherein the direction of the movement corresponds towhether the light detector detects an increasing series or a decreasingseries of detected light intensities over time.

There is moreover provided in accordance with an embodiment of thepresent invention a proximity sensor for determining directionalmovement of an object along a slider control, including a housing, alight transmissive cover mounted in the housing having an exposed uppersurface for a slider control, including a pattern of light-transmissiveportions separated by opaque or reflective portions, wherein the sizesof the light-transmissive portions, or of the opaque or reflectiveportions, increase across the pattern, a light pulse emitter mounted inthe housing for projecting light above the cover, a light detectormounted in the housing for detecting intensities of projected light thatis reflected into the cover by a reflective object, wherein the amountof light reflected by the object into the cover depends upon the sizesof the light-transmissive portions beneath the object, and a processorconnected to the light detector for determining directional movement ofthe object across the pattern, wherein the direction of the movementcorresponds to whether the light detector detects an increasing seriesor a decreasing series of detected light intensities over time.

There is additionally provided in accordance with an embodiment of thepresent invention a handheld electronic game device, including ahousing, a communicator mounted in the housing for communicating with aninternet game server, a display mounted in the housing for rendering aportion of a game user interface received by the communicator from thegame server and sensors mounted in the housing and connected to thecommunicator for detecting a second game device placed nearby, whereinthe communicator communicates detection information, regarding a nearbysecond game device, provided by said sensors to the game server.

There is further provided in accordance with an embodiment of thepresent invention an internet gaming system including an internet gameserver, and a number, greater than one, of game devices, each of whichis a handheld electronic game device in communication with the gameserver, each game device including a housing, a communicator forcommunicating with the game server, a display mounted in the housing forrendering a respective portion of a game user interface (UI) received bythe communicator from said game server, and sensors mounted in thehousing and connected to the communicator for detecting presence of aneighboring game device, wherein the game server determines the size ofeach respective portion of the game UI based on the number of the gamedevices.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and appreciated fromthe following detailed description, taken in conjunction with thedrawings in which:

FIG. 1 is a diagram of a prior art, light-based touch screen having 16LEDs and 16 PDs;

FIG. 2 is a simplified diagram of a proximity sensor for detectingtwo-dimensional coordinates of an object in a two-dimensional detectionarea, in accordance with an embodiment of the present invention;

FIG. 3 is a simplified diagram of a touch screen system using theproximity sensor of FIG. 2, in accordance an embodiment of the presentinvention;

FIGS. 4 and 5 are exploded views of an optical proximity sensor, inaccordance with an embodiment of the present invention;

FIG. 6 is a view from above of an optical proximity sensor, inaccordance with an embodiment of the present invention;

FIGS. 7-12 are simplified diagrams of emitted and reflected light beamsused in an optical proximity sensor, in accordance with an embodiment ofthe present invention;

FIGS. 13 and 14 are illustrations of touch detection maps, in accordancewith an embodiment of the present invention;

FIG. 15 is a simplified illustration of a lens array with alternatingemitters and detectors, in accordance with an embodiment of the presentinvention;

FIGS. 16-18 are simplified touch detection maps used for illustratingthe algorithms used to calculate a touch location using an opticalproximity sensor, in accordance with an embodiment of the presentinvention;

FIG. 19 illustrates an interpolation of detection signals, in accordancewith an embodiment of the present invention;

FIG. 20 illustrates a Hough transform, in accordance with an embodimentof the present invention;

FIG. 21 is a detection map, in accordance with an embodiment of thepresent invention;

FIGS. 22 and 23(a)-(f) are simplified touch detection maps for varioustouch screen system embodiments, in accordance with the presentinvention;

FIGS. 24 and 25 are simplified illustrations of a dual-resolutionsensor, in accordance with an embodiment of the present invention;

FIGS. 26(a) and (b) are simplified illustrations of two detection mapsused in a dual-resolution sensor, in accordance with an embodiment ofthe present invention;

FIG. 27 is a simplified view from above of LEDs and PDs on a PCB for adual-resolution sensor, in accordance with an embodiment of the presentinvention;

FIG. 28 is a simplified cross-section illustration of a dual-resolutionsensor, in accordance with an embodiment of the present invention;

FIG. 29 is a simplified illustration of a dual-display laptop, inaccordance with an embodiment of the present invention;

FIG. 30 is a simplified illustration of a portion of a dual-displaylaptop, in accordance with an embodiment of the present invention;

FIG. 31 is a simplified illustration of a PC, in accordance with anembodiment of the present invention;

FIG. 32 is a simplified illustration of the keyboard of the PC of FIG.31, in accordance with an embodiment of the present invention;

FIG. 33 is a simplified illustration of a PC trackpad, in accordancewith an embodiment of the present invention;

FIG. 34 is a simplified illustration of a transparent PC keyboard, inaccordance with an embodiment of the present invention;

FIG. 35 is a simplified side perspective view of the transparentkeyboard of FIG. 34, in accordance with an embodiment of the presentinvention;

FIG. 36 is a simplified illustration of a secondary display thatprovides keyboard and GUI functionality, in accordance with anembodiment of the present invention;

FIG. 37 is a simplified illustration of a laptop keyboard, in accordancewith an embodiment of the present invention;

FIG. 38 is a simplified cross-section of the laptop keyboard of FIG. 37,in accordance with an embodiment of the present invention;

FIG. 39 is a simplified illustration of a PC with proximity sensors fordetecting wave gestures that approach a side edge of the display, inaccordance with an embodiment of the present invention;

FIG. 40 is a simplified illustration of three views of an exemplaryfour-button keypad chassis, situated over a virtual keypad portion of atouch panel, in accordance with an embodiment of the present invention;

FIG. 41 is a simplified illustration of a cross-section of an exemplaryfour-button keypad chassis, situated over a virtual keypad portion of atouch panel, in accordance with an embodiment of the present invention;

FIGS. 42(a)-(c) are simplified illustrations of a spring-resilient keythat is released and depressed, in accordance with an embodiment of thepresent invention;

FIGS. 43(a) and (b) are simplified illustrations of a cross-section of abutton comprised of an elastic, resilient material such as rubber, inaccordance with an embodiment of the present;

FIGS. 44(a)-(d) are simplified illustrations of an alternative buttonconfiguration, in accordance with an embodiment of the presentinvention;

FIG. 45 is a simplified illustration of an arrangement of micro lensarrays between a keyboard display and a fiber optic face plate key, inaccordance with an embodiment of the present invention;

FIG. 46 is a simplified illustration of a key or button, in accordancewith an embodiment of the present invention;

FIG. 47 is a simplified illustration of a slider control, in accordancewith an embodiment of the present invention;

FIG. 48 is a simplified illustration of various detection patterns ofgestures using the slider control of FIG. 47, in accordance with anembodiment of the present invention;

FIG. 49 is a simplified illustration of an alternative slider control,in accordance with an embodiment of the present invention;

FIGS. 50-53 are simplified illustrations of a game accessory, inaccordance with an embodiment of the present invention;

FIG. 54 is a simplified illustration of a 3-dimensional sensor usingmultiple optical proximity sensors, in accordance with an embodiment ofthe present invention;

FIG. 55 is a simplified illustration of a handheld electronic gamedevice having a communicator for communicating with an internet gameserver, in accordance with an embodiment of the present invention;

FIG. 56 is a simplified illustration of an internet game rendered on ahandset, in accordance with an embodiment of the present invention;

FIG. 57 is a simplified illustration of two handsets being used togetherto render an internet game, in accordance with an embodiment of thepresent invention;

FIG. 58 is a simplified illustration of a two-panel display for aninternet game, the display being made up of two handsets, in accordancewith an embodiment of the present invention;

FIG. 59 is a simplified illustration of a four-panel display for aninternet game, the display being made up of four handsets, in accordancewith an embodiment of the present invention; and

FIG. 60 is a simplified illustration of a configuration of the four gamedevices of FIG. 59, whereby the game GUI is distributed among the fourdisplays according to each display's relative position and orientation,as detected by sensors and communicated to a game server, in accordancewith an embodiment of the present invention.

The following tables catalog the numbered elements and list the figuresin which each numbered element appears. Similarly numbered elementsrepresent elements of the same type, but they need not be identicalelements.

Numbered Elements Element Description FIGS.  10 key or button 40-44  12chassis 40-44  14 touch panel 40-43  16 emitter/photo-detector 40  20light beam 40-44  22 lens 41-43  24 spring 42  30 cavity 44 51-54micro-lens array 45, 46  55 aperture mask 45, 46  56 display 45, 46  57fiber optic face plate 45 (FOFP) input surface  58 FOFP 46  59 key orbutton 46 100 screen  1, 28 101-103, emitters 1-4, 6-12, 15, 25, 111,130 27, 38, 47, 49-53 131 primary display 29, 31, 39 132 secondarydisplay 29, 30, 37 133 keyboard 31, 32 134 track board 31, 33 135keyboard 34, 35 136, 137 GUI control 36 139 liquid layer 38 140 lightblocker 38 141 plastic film 38 142-145 display 60 201-208, 210,photo-detectors 1-4, 6-8, 10-12, 15, 25, 211, 215, 240 27,28, 38, 47,49-53 301 light guide  3 302, 303 lenses  3 304 light guide 28 305-307reflective facets 28 310 light guide 4, 5 311 lens 4, 6, 8-11 312 lensarray 2, 15, 25 320, 321 light barrier 4-6 331 bezel 30 332 light guide37 333 TIR upper light guide 47, 49 334 TIR lower light guide 47 335opaque elements 47, 49 336, 401 light beams  3, 49 402 reflected lightbeam  3 403-405 light beams 2, 15, 25 406-409 reflected light beams  2,15 410 light beams  9-12 411-413 reflected light beams 2, 7, 10-12 420light beam  8 421 reflected light beams  8 432 light beams 37 433 TIRlight 37 434 FTIR light 37 501, 510, 511 touch sensor bar 4-6, 12, 24,54 512-517 proximity sensor 2, 32, 33 518 game device sensor 55, 60 601,602 casing 4, 5 603 PCB 4, 5, 27, 28 701 controller  6 702 processor  1703 communications processor 55, 60 901 object  3 902-909 position indetection plane 2, 15, 19 910 object  6 911 screen  9, 54 912 imageplane  8 913, 914 point in image plane  8 915 angle  8 916 object plane 8 917 concentric shapes 14 919 area in detection map 22 921, 922detection zone 24 924 finger 47, 49 930 location on detection map 21 931area in detection map 21 932 line in detection map 21 933 elastic band50-53 934 slingshot pad 50-53 935 extension 51-53 939 arrow 58 950 hinge54 952-954 interpolated position 19, 20 and direction 955-957 candidateellipse 20 976 PCB 50-53 983, 984 communications processor 57 991 server55-57, 60    994-997 handset/game console 55-59 998, 999 detection zone56-59

DETAILED DESCRIPTION

Aspects of the present invention relate to light-based touch screens andlight-based touch surfaces. Throughout this specification, the term“touch screen” includes a touch surface that does not include anelectronic display, inter alia, a mouse touchpad as included in manylaptop computers and the back cover of a handheld device. It alsoincludes an unenclosed airspace adjacent to the sensor provided by thepresent invention.

According to embodiments of the present invention, a light-based touchsensor includes a plurality of infra-red or near infra-redlight-emitting diodes (LEDs) and a plurality of photodiodes (PDs)arranged along one edge of a detection plane. In some embodiments, thedetection plane is the surface or interface area of a touch screen, asdefined above. The LEDs project collimated light along the detectionplane, and when this light is reflected by an inserted object, such as afinger or a stylus, the reflected light is detected by the PDs. Thegeometry of the locations of the activated LED and the PD that detectsthe reflected light, suffices to determine two-dimensional coordinatesof the pointer within the detections area by triangulation. The LEDs andPDs are selectively activated by a processor. Generally, each LED and PDhas I/O connectors, and signals are transmitted to specify which LEDsand which PDs are activated.

Reference is made to FIG. 2, which is a simplified diagram of aproximity sensor for detecting two-dimensional coordinates of an objectin a two-dimensional detection area, in accordance with an embodiment ofthe present invention. FIG. 2 shows proximity sensor 512 featuring a rowof alternating emitters and detectors along the bottom edge, an array oflenses 312 along the upper edge and processor 702 at the left edge. Notall of the emitters and detectors are numbered in order to simplify theillustration. Thus, only emitters 101-103 and detectors 202-208 arenumbered in FIG. 2. The alternating arrangement of emitters anddetectors is illustrated by emitters 101-103 and detectors 206-208.

Each emitter is situated on the optical axis of a respective collimatinglens in array 312. In FIG. 2 emitters 101-103 are shown projectingrespective light beams 403-405.

FIG. 2 also shows reflected light beams for each detector. Five of theseare numbered 406-409 and 413. Each lens in array 312 transmits reflectedlight to the two detectors neighboring the lens's emitter. For example,the lens opposite emitter 102 directs reflected beam 413 onto detector207 and also directs reflected beam 409 onto detector 208. As will beexplained below, the detectors are positioned along the lens's objectplane to receive maximum intensity from beams that enter the lens at aparticular angle. This enables determining a location in thetwo-dimensional area corresponding to each emitter-detector pair. InFIG. 2 these locations are the intersections between emitter beams andreflected beams. In FIG. 2 five such locations are numbered 902-906.

According to an embodiment of the present invention, each emitter issynchronously co-activated with each of the detectors by processor 702.If reflected light is detected during a co-activation, it indicates thatan object is located in the vicinity of the corresponding intersectionlocation between the activated emitter beam and the correspondingreflected beam for the co-activated detector, as illustrated in FIG. 2.Processor 702 calculates the object's coordinates by determining anemitter-detector pair among the co-activated emitter-detector pairs, forwhich the detector detects a maximum amount of light, and identifyingthe position associated therewith. For example, the maximum detection isidentified for the emitter-detector pair 102-202, namely, when emitterbeam 404 is reflected along beam 408. The position corresponding to thisdetection is position 902 in the detection plane. Processor 702determines additional positions that are associated with co-activatedemitter-detector pairs and that neighbor the identified position of themaximum detection, e.g., emitter-detector pair 102-203 whosecorresponding position is 903 and emitter-detector pair 101-202 whosecorresponding position is 905. Additional detections and theircorresponding positions can also be used, e.g., detections correspondingto positions 904 and 906. Processor 702 calculates a weighted average ofthe identified position of the maximum detection and the thus-determinedadditional positions, wherein each position's weight in the averagecorresponds to a degree of detection of the reflected light beam for theemitter-detector pair to which that position is associated.

Processor 702 is operable to synchronously co-activate one emitter withmore than one detector simultaneously. In some embodiments, processor702 calculates the object location using the Hough transform asdescribed herein below.

Emitters such as LEDs and detectors such as photo diodes (PDs) typicallycome mounted on individual substrates and encased in individual lenscovers. In order to reduce the cost of proximity sensor 512, in someembodiments the emitters and detectors are mounted as bare diodes on aPCB or other substrate in proximity sensor 512 without individual lensesand without individual substrates. The lens array 312 serves as the onlylens for these diodes. In this case proximity sensor 512 can be viewedas a large, multi-diode component. This component can bepre-manufactured and inserted either by an ODM or by an end user into adevice to provide touch detection.

For example, this component can be placed above or below a car window toenable the user to perform tap and gesture input on the car window.Processor 702 includes a communicators processor e.g., BLUETOOTH® forcommunicating wirelessly with the car stereo or with a user's phone.Similarly, this component can be placed above or below a window in ahouse or on the wall in a house to enable the user to perform tap andgesture input on the window or wall. A transparent sheet with digits andicons can be placed on or in the window glass or on the wall to indicatewhat input operations the user's touches at each location activate.

In the description, proximity sensor 512 is also referred to as touchsensor bar 501 and touch sensor bar 510.

Reference is made to FIG. 3, which is a simplified diagram of a touchscreen system using proximity sensor 512, in accordance an embodiment ofthe present invention. FIG. 3 shows a touch sensor bar 501 detectinglight reflected by a remote object 901. Touch sensor bar 501 includesfive PDs, 201-205. An LED is inserted between each pair of PDs. Thus,there are 4 LEDs in touch sensor bar 501. However, only one of the LEDs,LED 101, is shown in FIG. 3.

Touch sensor bar 501 includes a light guide 301 in front of the LEDs andPDs, that performs two functions: first, it collimates light from thelight emitting diodes and projects it across the screen surface, asillustrated by light beams 401; second, it focuses reflected light 402entering the light guide 301 at fixed angles, onto the photodiodes.Thus, light guide 301 includes a connected series of collimating lenses,of which lenses 302 and 303 are indicated in FIG. 3. Lens 302 is showncollimating the emitter 101 beams, and lens 303 is shown focusingreflected light 402 entering the light guide 301 at a particular fixedangle onto photodiode 205.

Reference is made to FIGS. 4 and 5, which are exploded views of a touchdetection apparatus, in accordance with an embodiment of the presentinvention. FIG. 4 shows an exploded view of touch sensor bar 510, viewedfrom above. In between top and bottom casing parts 601 and 602, a PCB603 and light guide 310 are shown. PCB 603 has a row of alternating LEDs101 and PDs 201, whereby the outermost diodes at both ends of the roware PDs 201. Thus, there are 11 PDs interleaved with 10 LEDs on PCB 603.FIG. 3 also shows light guide 310 being formed of 10 collimating lenses311—one lens directly opposite each LED. As mentioned above, eachcollimating lens 311 performs two functions: collimating outgoing beamsand focusing incoming reflected beams onto a PD. The LED is situated atthe focus of its opposite lens. The lateral offset of each PD from thisfocal point ensures that the lens will only direct incoming beams withina narrow range of angles onto the PD. Incoming beams whose angle ofincidence on lens 311 is greater or less than the narrow range of anglesare focused away from the target PD.

In order to prevent stray LED light from saturating a neighboring PD, aseries of light barriers 320-321 separates each LED from its neighboringPDs. FIG. 5 shows another exploded view of touch sensor bar 510, viewedfrom below. The light barriers 320 and 321 are shown protruding from theunderside of top casing 601.

Reference is made to FIG. 6, which is a view from above of a touchdetection apparatus, in accordance with an embodiment of the presentinvention. FIG. 6 shows a view of touch sensor bar 510 from above. FIG.6 shows alternating row of LEDs 101 and PDs 201, each diode isolated bybarriers 320 and 321; lenses 311 opposite each LED 101 and a controller701 for activating LEDs 101 and PDs 201 in a sequence and for receivingthe PD detection signals. Touch calculations performed based on the PDdetection signals are executed either by controller 701, or offloaded toa separate processing unit, e.g., a host.

Reference is made to FIGS. 7-12, which are simplified diagrams ofemitted and reflected light beams used in a touch screen system, inaccordance with an embodiment of the present invention. FIG. 7 showsdetection of a distant object 910 based on two sets of reflected beams411 and 412 detected by PDs 210 and 211, respectively. FIG. 7 shows howbeams from one emitter 111 are detected by two PDs 210 and 211.Reflected beams 411 and 412 each enter respective ones of lenses 311 atan angle whereby the lens focuses the beam into a respective PD.

FIG. 8 shows the design considerations for lens 311 and placement ofemitter 101 and PD 201. Lens 311 is aspherical and optimized to achievea flat image plane 912 to maintain focus on both LED 101 and PD 201simultaneously. LED 101 sits on the optical axis, centered on lens 311.Point 913 is the image of LED 101 in image plane 912. PD 201 sits at theedge of the field of view. Point 914 is the image of PD 201 in imageplane 912. In terms of an image captured through the lens on objectplane 916, LED 101 is the center pixel and PD 201 is a pixel at the edgeof the captured image. The field of view for PD 201 is determined by thePD chip size, seen through the width of lens 311. Rays that hit lens 311from an angle outside the field of view of PD 201 will form an image inthe same plane 916 but somewhere between LED 101 and PD 201. Thus, theserays will not be captured by PD 201.

Angle 915, between emitter 101 beams 420 and reflected PD 201 beams 421,is selected to fit the intended shape of the active touch-detectionarea. When the active touch-detection area is square, angle 915 is thediagonal of half a square, i.e., tan⁻¹(½)≈26.6°. When the depth of viewis longer than the width of the touch sensor bar, angle 915 is smaller.

FIG. 9 shows a side view of LED 101 projecting light beams 410 above andacross the surface of screen 911. In addition to being collimated bylens 311, beams 410 are directed slightly upwards, away from the screensurface. This reduces the amount of light reflected by the surface ofscreen 911 in order to maximize the light utilized for touch detection.

FIG. 10 shows a view from above of one collimating lens 311, an emitter101 and a PD 201. Reflected light beams approaching lens 311 at an angleof incidence between that of beams 410 and 411 are focused on a locationbetween emitter 101 and PD 201. Reflected light beams approaching lens311 at an angle of incidence more acute than beam 411 are focused on alocation above PD 201. Thus, the lens and PD arrangement ensures thatthe system is sensitive to reflected light entering lens 311 at aspecific angle.

FIG. 11 shows the lens and components of FIG. 10 from a perspectiveview.

FIG. 12 shows beams 411 and 412 reflected by an object 910 at distance 3from touch detection bar 510. Based on the detection angle for which thePDs and lenses are configured, as described above, the greatestdetection signal is generated at PDs 210 and 211. Thus, the touchlocation is determined to be opposite the activated emitter 111, at adistance 3. These coordinates are easily converted to x, y screencoordinates. If, for example, the touch location were along beams 410but at a distance 2 from touch detection bar 510, the maximum detectionsignal would arrive at PDs 212 and 213. Similarly, if the touch locationwere along beams 410 but at a distance 1 from touch detection bar 510,the maximum detection signal would arrive at PDs 214 and 215. Moregenerally, each unit of distance along the emitter beam corresponds to aPD offset from the emitter. Thus, PDs 214 and 215 are at offset 0 fromemitter 111, PDs 212 and 213 are at offset 1, and PDs 210 and 211 are atoffset 2. Right and left detection angles are illustrated by beams 411and 412.

Reference is made to FIGS. 13 and 14, which are illustrations of touchdetection maps, in accordance with an embodiment of the presentinvention. FIG. 13 shows the PD offsets mapped to corresponding touchlocations on the screen for light beams from emitters, 0-9. In FIG. 13PD offsets are indicated as sensor offsets, and emitter indices areindicated as source indices. Each emitter beam is represented by avertical line beginning at one of the source indices. Each vertex in thediamond pattern on the mapped touch sensitive area corresponds to atouch location on the screen, and the dashed diagonal lines representreflected beams at the specific right and left detection angles. Theheight of each vertex corresponds to its PD offset from the emitter.Thus, although the PDs are interleaved in a single row with theemitters, the PD offsets are arranged along a second axis in FIG. 13 forclarity.

In the example described above, each detector receives beams from twolenses and is situated at a first location within the first lens'sobject plane at the opposite location with the second lens's objectplane. As a result, it is positioned to detect reflected beams enteringthe first lens at an angle θ with respect to the lens's optical axis,and reflected beams entering the second lens at an angle −θ to theoptical axis. As a result, many of the positions associated with a firstemitter-detector pair are also associated with a second emitter-detectorpair. In order to provide more unique positions associated withemitter-detector pairs, the detector is situated at non-symmetricallocations with respect to its two lenses. This is illustrated in FIG.15.

Reference is made to FIG. 15, which is a simplified illustration of alens array 312 with alternating emitters and detectors, in accordancewith an embodiment of the present invention. FIG. 15 shows the detectorbeing at two non-symmetrically opposite locations with respect to thetwo lenses of lens array 312. Thus, emitter beam 403 is intersected attwo different locations 907 and 908 by reflected beams 407 and 406. Insome embodiments, each detector is positioned at a slightly differentpair of locations within the object planes of its lenses. This providesa non-uniform distribution of positions associated with theemitter-detector pairs.

Touch Coordinate Algorithm

This section describes in detail the operations performed to determine atracked object's location. As explained in the previous section, foreach activated emitter any of the PDs may receive the focused, reflectedbeams depending on the distance between the emitter and the reflectingobject. Therefore, a scan of the entire screen outputs a table of PDdetection values, where columns correspond to LEDs and rows correspondto PDs. Thus, for a detector having 10 LEDs and 11 PDs, the output tablehas 11 rows and 10 columns, wherein, the 11 entries in column 1 containthe detection values at each PD when emitter 1 is activated, the 11entries in column 2 contain the detection values at each PD when emitter2 is activated, etc. TABLE I is an example table containing rawdetection values.

TABLE I Raw detection values LED LED LED LED LED LED LED LED LED LED 0 12 3 4 5 6 7 8 9 PD 0 2 3 7 4 4 2 6 3 6  0 PD 1 2 1 3 4 3 3 5 5 5  1 PD 41 1 0 8 5 13 11 5 5  2 PD 3 1 1 1 28 14 7 4 4 3  3 PD 2 5 2 0 2 141 10 76 8  4 PD 3 8 3 1 1 4 6 4 5 6  5 PD 6 10 4 1 8 4 1 1 8 9  6 PD 6 6 6 6 8144 4 2 3 6  7 PD 10 5 9 7 6 25 28 3 2 2  8 PD 8 4 8 4 5 1 5 2 1 1  9 PD4 2 5 1 5 4 5 5 3 2 10

The two maxima in TABLE I, namely, raw detection values 141 and 144, areobtained from PD 4 and PD 7, respectively, when LED 5 is activated. PD 4and PD 7 have an offset of 1 from LED 5, as PDs 5 and 6 are theimmediate left and right neighbors of LED 5 and have an offset of 0.

The amount of light reflected by a near object onto a PD at offset 0 or1 from the activated LED is greater than the amount of light reflectedby a distant object onto a PD at offset 7 or 8 from the activated LED.Indeed, the greater the PD offset, the less light will reach the PD,assuming all other parameters remain constant. The PD value is digitizedby an A/D converter having a given resolution, such as 12 bits or 16bits. In order to fully utilize the range of values, in certainembodiments each emitter is activated with different amounts of current,or for different durations, depending on the offset of the target PD.The greater the offset, the greater the current and/or activation time,in order to utilize the full range of values without the risk ofreaching the maximum detection value and possibly overflowing thatvalue. Other factors contribute to the range of possible or expected PDdetection values including the height of the lens 311 and thereflectivity of the pointing object. In particular, a greater lensheight above the screen surface admits more light onto the target PD. Insome embodiments, the amounts of expected PD detection values for thedifferent PD offsets are determined heuristically based on experiment.

In some embodiments, the A/D converter outputs more bits than are usedby the processor to calculate the touch location. For example, in someembodiments the A/D converter outputs 12-bit values and the processoruses 8-bit values. In these cases, it is important to determine themaximum expected 12-bit value. Based on this maximum, the system willremove most-significant-bits (msb) only when there is no risk that thevalue contains non-zero values in the removed msb. If the risk ofoverflow prevents the system from discarding msb, the system will removeleast-significant-bits (lsb) to arrive at an 8-bit value. These maximumvalues are also determined by heuristics and depend on the PD offset.

Heuristics are also used to prepare a reference detection value for eachLED-PD pair. Thus, each of the detected PD values in the detection tabledescribed above is divided by a respective reference value to normalizeall values in the table to a range of 0-1. FIG. 14 shows a detection mapof normalized detection values for a touch corresponding to LED 2 andthe PDs at offset +/−5. Since there is no corresponding PD at offset −5from LED 2, only the PD at offset +5 generates this maximum detectionsignal. The detection map of FIG. 14 includes concentric solid- anddashed-line shapes 917 where each inner shape is greater than its outerneighbor, such that the maximum detection signal is at the center. IfFIG. 14 were to be rendered in color or varying degrees of grayscale,the innermost shape would be darkest, and the shapes would becomeprogressively lighter as they expand. However, color and shading hasbeen removed from FIG. 14 in order to render it in pure black and white.

Not only is the absolute value of a detection signal useful fordetermining the touch location, but the relationship between neighboringsignals is also an important factor.

Reference is made to FIGS. 16-21, which are simplified touch detectionmaps for illustrating the algorithms used to calculate a touch locationin a touch screen system, in accordance with an embodiment of thepresent invention. FIG. 16 shows a portion of the detection map of FIG.13. As described above, the solid vertical lines represent emitterbeams. More precisely, each vertical line represents the center of thebeams from a given emitter. The emitter beams are considered to have anormal, bell-shaped distribution around the center of the beam.Similarly, the solid diagonal lines in FIG. 16 represent the optimalreflected beam that generates a maximum detection value at a PD at agiven offset. The detection values for beams parallel to, and inbetween, these diagonal beams are considered to have a normal,bell-shaped distribution of detection at the PD with the given offset.These distribution properties provide the ability to determine locationsbetween the solid vertical and diagonal lines, or between the verticesin the detection map of FIG. 13 that indicate points of maximumdetection, by comparing neighboring detection signals. Thus, the pointof contact is based on six lemmas listed below.

Lemma 1:

If the reflecting object is translated parallel to the diagonaldetection lines of the PDs, the relationship between detection signalsof neighboring PDs detecting the same LED remains constant.

Lemma 1 is illustrated in FIG. 16. FIG. 16 shows a portion of thedetection map of FIG. 13 wherein the three solid vertical linesrepresent portions of 3 emitter beams and the four solid diagonal linesrepresent 4 detector beams. As mentioned above, points of maximumdetection levels are at the vertices where an emitter beam crosses adetector beam. Three such vertices are labeled in FIG. 16, namely p0, r1and d1, each label being to the right of its corresponding vertex. In acase where the touch object is at the midpoint between p0 and d1, theratio of the detection signal representing point p0 and the detectionsignal representing point d1 would be roughly equal. Moreover, as longas the touch object is translated along the dashed diagonal line betweenp0 and d1, this ratio remains constant. Thus, based on the ratio betweenthe two highest detection signals of neighboring PDs detecting the sameLED, a line can be drawn parallel to the diagonal dashed line in FIG.16, and the touch location should be somewhere on that drawn line. Thedrawn line will be closer to vertex p0 or d1 depending on the magnitudeof this ratio.

Lemma 2:

If the reflecting object is translated parallel to the vertical emitterlines of the LEDs, the relationship between detection signals of one PDdetecting two, neighboring LEDs remains constant.

Lemma 2 is also illustrated in FIG. 16. Vertex p0 represents an LED beamwhose reflection is detected at a PD with an offset n from the activatedLED. Vertex r1 represents a neighboring LED beam whose reflection isdetected at a PD with an offset n+1 from the activated LED. However,since the activated LED for r1 is a neighbor of the activated LED forp0, the same PD used for p0, whose offset is n, is used for r1, sincethis PDs offset from the r1 LED is n+1. In a case where the touch objectis at the midpoint between p0 and r1, the ratio of the detection signalrepresenting point p0 and the detection signal representing point r1would be roughly equal. Moreover, as long as the touch object istranslated along the dashed vertical line between p0 and r1, this ratioremains constant. Thus, based on the ratio between the two highestdetection signals of one PD detecting two, neighboring LEDs, a line canbe drawn parallel to the vertical dashed line in FIG. 16, and the touchlocation should be somewhere on that drawn line. The drawn line will becloser to vertex p0 or r1 depending on the magnitude of this ratio.

Lemma 3:

Combining Lemmas 1 and 2 provides a rhomboid area in which the touch islocated. Three of the vertices of this rhomboid area are vertices r1, p0and d1. Moreover, the exact touch location is at the point ofintersection between the drawn line of Lemma 1 and the drawn line ofLemma 2.

Lemmas 1-3 apply to small touch objects that reflect light from a singlepoint. Larger touch objects reflect along a side of the object,perpendicular to the LED beams. Thus, in the case of a large touchobject, there is a wider, more even distribution of maximum detectionvalues representing a series of reflection points that are equallydistant from their respective LEDs. Lemmas 4-6 relate to large touchobjects.

Lemma 4:

If the reflecting object is translated perpendicular to the verticalemitter lines of the LEDs, the relationship between detection signals ofneighboring PDs detecting the same LED remains constant.

Lemmas 4-6 are illustrated in FIG. 17. FIG. 17 shows a portion of thedetection map of FIG. 13 wherein the three solid vertical linesrepresent portions of 3 emitter beams and the four solid diagonal linesrepresent 4 detector beams. As mentioned above, points of maximumdetection levels are at the vertices where an emitter beam crosses adetector beam. Three such vertices are labeled in FIG. 17, namely p0, r1and d1, each label being to the right of its corresponding vertex. In acase where a large reflecting object is placed between p0 and d1, theratio of the detection signal representing point p0 and the detectionsignal representing point d1 would be roughly equal. Moreover, as longas the touch object is translated along the dashed horizontal linebetween p0 and d1, this ratio remains constant. Thus, based on the ratiobetween the two highest detection signals of neighboring PDs detectingthe same LED, a line can be drawn parallel to the diagonal dashed linein FIG. 17, and the touch location should be somewhere on that drawnline. The drawn line will be closer to vertex p0 or d1 depending on themagnitude of this ratio.

Lemma 5:

If the reflecting object is translated parallel to the vertical emitterlines of the LEDs, the relationship between detection signals havingsimilar offsets from their respective LEDs remains constant.

Because Lemma 5 relates to wide reflective objects that reflect light atmany locations equally-distant from the row of LEDs, the two highestdetection values will come from neighboring PDs having similar offsetsfrom their respective LEDs. Accordingly, Lemma 5 is also illustrated inFIG. 17. Vertex p0 represents an LED beam whose reflection is detectedat a PD with an offset n from the activated LED. Vertex r1 represents aneighboring LED beam whose reflection is also detected at a PD with anoffset n from its activated LED. In a case where the touch object is ata point between p0 and r1, the ratio of the detection signalrepresenting point p0 and the detection signal representing point r1would be roughly equal. Moreover, as long as the touch object istranslated along the dotted vertical line between p0 and r1, this ratioremains constant. Thus, based on the ratio between the two highestdetection signals of two neighboring PDs detecting two, neighboringLEDs, a line can be drawn parallel to the vertical dashed line in FIG.17, and the touch location should be somewhere on that drawn line. Thedrawn line will be closer to vertex p0 or r1 depending on the magnitudeof this ratio.

Lemma 6:

Combining Lemmas 4 and 5 provides a rectangular area in which the touchis located. Three of the vertices of this rectangular area are verticesr1, p0 and d1 in FIG. 17. Moreover, the touch location is at the pointof intersection between the drawn line of Lemma 4 and the drawn line ofLemma 5.

According to certain embodiments of the invention, the touch location isderived based on a combination of Lemmas 1-6. This method proceeds inthree steps. Step 1 calculates two interpolated points along twoneighboring LED beams. Step 2 draws a line connecting the twointerpolated points. Step 3 calculates a point along the line drawn atstep 2 by interpolating the amplitudes of the two endpoints calculatedat step 1. This method is described with reference to FIG. 18.

FIG. 18 shows a portion of the detection map of FIG. 13, wherein thethree solid vertical lines represent portions of 3 emitter beams and thefour solid diagonal lines represent 4 detector beams. As mentionedabove, points of maximum detection levels are at the vertices where anemitter beam crosses a detector beam. Six such vertices are labeled inFIG. 18, namely, p0, d0 and d1, each labeled to the right of acorresponding vertex, and, r1 a, r1 b and r1 c, each labeled to the leftof a corresponding vertex. When performing this method, point p0 is themaximum detection signal for this touch object. The PD for point p0 hastwo neighboring PDs, one to the left (for detection point d1) and one tothe right (for detection point d0), that also detect the same LED asused for p0. The PD having the higher detection signal is used. In FIG.18, this second detection signal of the neighboring PD detecting thesame LED as p0, is d1. The normalized detection signals at p0 and d1 areinterpolated to generate a new location, c0, on the LED beam betweenvertices p0 and d1. In addition to location c0, the interpolation alsocalculates an amplitude of the signal at c0.

Next, the method calculates a second new location, along a neighboringLED beam. Thus, relevant reflections from left and right neighboringbeams are compared and the beam returning the greater signal is used. InFIG. 18, the beam to the left of the p0 beam is selected. Vertex r1 buses the same PD as used for p0, but it detects a left-neighbor LED.Next, the normalized signals at r1 a and r1 c are compared and thegreater signal is selected. The r1 b detection signal and the selectedr1 a/r1 c signal are interpolated to generate a new location, c1, on theLED beam between vertices r1 b and r1 a or r1 c. In addition to locationc1, the interpolation also calculates an amplitude of the signal at c1.

The two points c0 and c1 define a line along which the touch location isto be found. This is the dashed line in FIG. 18. The calculated signalamplitudes at c0 and c1 are interpolated to determine the touch locationalong this line.

As mentioned above, the relationship between two signals is expressed asthe quotient (q) between them. The source beam light intensity isassumed to behave as a normal distribution on both sides of the beamcenter line. The reflection intensity is proportional to the lightintensity. The detection signal value of a reflection is also assumed tobe distributed as a normal distribution on both sides of the detectioncenter line. The standard deviations of these distributions varyaccording to the distance of the reflecting object, but are assumed tobe constant within a small range of distances.

Since the reflection (r) and detection (d) intensities of a signal s−f_(sr) and f_(sd) respectively, are of the normal distribution, theyare expressed as the Gaussian function:

$\begin{matrix}{{f_{si} = {{p_{i}(x)}A\; e^{- \frac{{({x - x_{si}})}^{2}}{2\sigma_{si}^{2}}}}},} & \left( {{EQ}.\mspace{14mu} 1} \right)\end{matrix}$

where i is r or d, x is the reflection location, x_(si) is the locationof the source beam or sensor detection line, p_(i)(x) is the typicalpeak strength at the current reflection distance, and A is theamplitude. The quotient between two intensities is then:

$\begin{matrix}{q_{s_{0},s_{1},i} = {\frac{f_{s_{1}i}}{f_{s_{0}i}} = {e^{- \frac{{({x - x_{s_{1}i}})}^{2} - {({x - x_{s_{0}i}})}^{2}}{2\sigma_{s_{0,1}i^{2\;}}}}.}}} & \left( {{EQ}.\mspace{14mu} 2} \right)\end{matrix}$

Assigning x∈[0,1], and approximating σ_(s) _(0,1) _(i)≈σ_(s) ₀_(i)≈σ_(s) ₁ _(i), EQ. 2 can be simplified to:

$\begin{matrix}{q_{s_{0},s_{1},i} = {e^{\frac{x - {1/2}}{\sigma_{s_{0,1}i^{2\;}}}}.}} & \left( {{EQ}.\mspace{14mu} 3} \right)\end{matrix}$

That gives the interpolated coordinate x:

$\begin{matrix}{{x = {\frac{1}{2} + {\sigma_{s_{0,1}i^{2}}\ln \; \frac{f_{s_{1}i}}{f_{s_{0}i}}}}},} & \left( {{EQ}.\mspace{14mu} 4} \right)\end{matrix}$

and the amplitude A:

$\begin{matrix}{A = {\frac{f_{si}}{p_{i}(x)}{e^{\frac{{({x - x_{si}})}^{2}}{2\sigma_{si}^{2}}}.}}} & \left( {{EQ}.\mspace{14mu} 5} \right)\end{matrix}$

In some embodiments, when the size and shape of the object to bedetected by the proximity sensor is known, the Hough transform is used.For example, when a finger is used to perform input, its expected shapewithin the detection plane is an ellipse of a known size. In this case,processor 702 is provided with a plurality of candidate ellipses withinthe detection plane. Processor 702 determines for which of theco-activated emitter-detector pairs the detector generates a detectionsignal, and identifies the positions associated therewith. Next,processor 702 interpolates the detection signals for any two of theco-activated emitter-detector pairs whose two associated positions areneighbors, to determine an intermediate location between those twoassociated positions. Processor 702 then assigns an orientation to eachintermediate location, the orientation being perpendicular to the lineconnecting the two neighboring associated positions. This process isillustrated in FIG. 19.

FIG. 19 shows positions 902-906 each associated with an emitter-detectorpair. Position 902 is interpolated with position 903 to produceintermediate location 952 having horizontal orientation. The detectionsignal corresponding to position 902 is, in this illustrative example,greater than the detection signal corresponding to position 903. Hence,the location of intermediate location 952 is closer to 902 than 903.Similarly, intermediate location 953 is interpolated using positions 904and 905, where the detection signal corresponding to position 904 isgreater than that corresponding to position 905; and intermediatelocation 954 is interpolated using positions 905 and 906, where thedetection signals corresponding to these positions are roughly equal,hence the location of 954 is at the midpoint between positions 905 and906.

For each candidate ellipse, processor 702 assigns a match value to thecandidate ellipse, the match value representing a degree of matchbetween an edge of the candidate ellipse and the location andorientation of an intermediate location. FIG. 20 shows four ellipses955-958. Interpolated location 953 is assigned a high match value toellipses 955 and 956 and a very low (or zero) match value to ellipses957 and 958 because the orientation of interpolated location 953 doesnot match that of its corresponding location in these ellipses.

Processor 702 calculates a sum of the thus-assigned match values foreach candidate ellipse, and designates that candidate ellipse with themaximum thus-calculated sum as being the location of the object in thedetection plane.

Implementation

The signals are filtered for maxima. A maximum is a signal greater thanits 8 immediate neighbors: top, bottom, left, right and four diagonalneighbors. For the portion of the touch-sensitive area in which areflective object produces two detection signals, namely, one at anoffset +n from the active LED and one at an offset −n, two maxima willbe generated by the reflective object. In this case, in someembodiments, only the greater of these two maxima is used. FIG. 21 showsmaximum 930.

As explained above, the maximum signal is one corner of an area in whichthe reflecting object is located. This area is a rectangle or rhombusconnecting adjacent neighbors. The area is chosen to include thestrongest signals. The deduced reflection location will be somewhereinside this area.

Next, two signals neighboring the maximum signal are compared, namely,the two PDs on either side of the maximum signal PD detecting the sameLED as the maximum signal. These correspond to vertices above and belowmaximum 930 in FIG. 21, along the same emitter beam. The greater ofthese two signals is selected, and accordingly, one side of therectangular, or rhomboid, object location area extends from the maximumsignal vertex to the selected neighboring vertex. In FIG. 21, the vertexabove maximum 930 was selected.

Next, the signals from neighboring LEDs to the left and right arecompared to decide whether to extend the area in which the reflectingobject is located to the left or right. On the left side, the twolocations directly left of the locations on the first area side, plusone more directly below them are used. On the right, it is the twopoints to the right, plus one more above them. The side that containsthe highest signal is the side the area is extended to. On the leftside, if the top-most signal is stronger than the bottom-most, the areain which the reflecting object is located is determined to be arectangle. If not, it is a rhombus extended to include the bottom-mostlocation. On the right side, the same comparison is made. If thebottom-most signal is stronger than the top-most, then the area in whichthe reflecting object is located is determined to be a rectangle. Ifnot, it is a rhombus that extends to include the top-most location. InFIG. 21, the area in which the reflecting object is located is a rhombusextended to the left and down, i.e., rhombus 931 with vertex 930 at itslower right corner.

As explained above, each pair of selected vertices representing tworeflection detections from one LED are interpolated to find two points(c0, c1, in FIG. 18) that define a line 932 on which the reflectingobject is located. Both the location and amplitude of the points arecalculated, as described above.

The same interpolation method is used again to find the reflectionlocation along this line and its amplitude. The amplitude may beinterpreted as reflectivity, which in turn is proportional to thediameter of the reflecting object.

At times, multiple, unconnected maxima are identified. In such cases,the interpolated location and reflectivity of each maximum iscalculated. Those coordinates found to have a reflectivity or amplitudevalue above a defined threshold are stored as reflective objectlocations. Thus, a frame representing the entire scanned touch area maycontain a list of simultaneous touch objects, each object having acorresponding location.

In a sequence of such frames, reflective objects in the frame at timet+1 are compared to the reflective objects of the previous frame, attime t. The objects in the two frames are paired using a greedy pairingalgorithm according to a minimum distance between paired objects. Pairedobjects are tracked as being the same object. New objects not paired areadded as new tracking targets, and old tracking targets not paired tonew ones are removed.

The location and reflectivity parameters of the tracked objects arecalculated as the old parameters (at time t), updated with a predictionbased on constant speed, and a fractional interpolation towards the newparameters (at time t+1). The detected location l_(d) is used to updateprevious tracked location l₀ together with the tracked velocity vectorv₀ to determine the updated location and velocity l₁ and v₁:

l ₁=(1−α)(l ₀ +βv ₀)+αl _(d),  (EQ. 6)

v ₁ =l ₁ −l ₀,  (EQ. 7)

where a is the relative weight applied to the detected (t+1) position inthe interpolation, and β represents how constant the velocity is assumedto be.

Reference is made to FIGS. 22 and 23(a)-(f), which are simplified touchdetection maps for various touch screen system embodiments, inaccordance with the present invention. As mentioned hereinabove, theoptical proximity sensor PDs are paired with lenses that optimizedetections of reflected light for an angle θ, indicated by the diagonallines shown in FIGS. 22 and 23(a)-(f). The vertical lines in FIGS. 22and 23(a)-(f) represent light emitted by the sensor LEDs. Detectionhotspots are points of intersection between the vertical emitter beamsand the diagonal optimized detection paths. These hotspots are indicatedby a small circle at each intersection.

FIG. 22 shows a triangular section 919 where objects are not detected bythe sensor. FIG. 23(a)-(f) illustrates how the size of the area in whichan optical proximity sensor can detect an object depends on the anglefor which the sensor's PDs are optimized. In FIG. 23(a) θ=20°; in FIG.23(b) θ=30°; in FIG. 23(c) θ=40°; in FIG. 23(d) θ=50°; in FIG. 23(e)θ=60°; and in FIG. 23(f) θ=70°. In the examples of 23(a)-(f) the maximumdistance from the sensor bar is 120 mm and the bar is 91 mm long with apitch between neighboring light elements along the bar of 7 mm. In FIG.23(a) the height of the screen (120 mm) is covered with detectionhotspots.

The density of these hotspots can be broken down into an optical xresolution, which is the pitch between neighboring light elements withinthe sensor bar, and an optical y resolution that depends on the angle θ.The examples illustrated in 23(a)-(f) show how increasing resolution inthe y dimension corresponds to shallower detection zones.

Accordingly, the present invention teaches a dual-resolution screenwhereby a narrow area adjacent to the sensor bar provideshigh-resolution touch detection and a second area further from thesensor bar provides low-resolution touch detection. Reference is made toFIGS. 24 and 25, which are simplified illustrations of a dual-resolutionsensor, in accordance with an embodiment of the present invention. FIG.24 shows touch sensor bar 511, a narrow, high-resolution detection zone921 and a low-resolution detection zone 922. One application for thisdual-resolution sensor is to provide a GUI wherein keypads and othertap-activated controls are placed in the high-resolution zone, andcoarse gestures such as sweep gestures and pinch gestures are supportedin the low-resolution zone.

Two solutions provide multiple resolution zones. A first solution placestwo detectors between every two emitters. Thus, every lens pitch has twodetectors and one emitter, and every lens directs four differentreflected beams onto four different detectors. This is illustrated inFIG. 25, which shows emitters 101-103 and detectors 201-204.

A second solution teaches a touch sensor bar in which some of the PDlenses are optimized for a first detection angle, e.g., θ₁=50°, andother PD lenses are optimized for a different detection angle, e.g.,θ₂=20°. The first detection angle provides a high-resolution detectionzone adjacent to the bar, and the second detection angle providesdetection further away from the sensor bar at a lower resolution.

Reference is made to FIGS. 26(a) and (b), which are simplifiedillustrations of two detection maps used in a dual-resolution sensor, inaccordance with an embodiment of the present invention. FIG. 26(a) showsa zone that extends 120 mm from the sensor but has a low optical yresolution of 20 mm, and FIG. 26(b) shows a detection zone near thesensor, having a higher optical y resolution of 6 mm.

In certain embodiments of the proposed dual-resolution sensor bar, thelayout alternating LEDs 101 and PDs 201 described hereinabove withreference to FIGS. 4 and 5 is maintained and PDs 101 are positioned toreceive maximum amount of light from a first detection angle θ₁. Inaddition, a second, parallel row of PDs is provided for receiving amaximum amount of light from a second detection angle θ₂. Thus, twice asmany PDs are used in the dual resolution sensor than in the sensor ofFIGS. 4 and 5, and the reflected light beam in the dual-resolutionsensor is split between the two PDs.

Reference is made to FIG. 27, which is a simplified view from above ofLEDs and PDs on a PCB for a dual-resolution sensor, in accordance withan embodiment of the present invention. FIG. 27 shows a top view of thelayout of light elements on PCB 603 in an embodiment of thedual-resolution sensor. FIG. 27 shows the first row of alternating LEDs101 and PDs 201 and a parallel row of PDs 202. The pitch between PDs 202in the second row is the same as that between PDs 201 in the first row.

Reference is made to FIG. 28, which is a simplified cross-sectionillustration of a dual-resolution sensor, in accordance with anembodiment of the present invention. FIG. 28 shows the lenses andplacement of the PDs in a dual resolution sensor. PD 202 provides thenarrow, high-resolution detection zone 921 near the sensor bar, and PD201 provides the longer, low-resolution detection zone 922 that extendsfarther away from the sensor bar. Shown in FIG. 28 are screen 100, PCB603 on which PDs 201 and 202 are mounted together with light guide 304.Light guide 304 includes three reflective facets: 305, 306 and 307.Light reflected by an object touching screen 100 enters light guide 304and is redirected downward by reflective facet 305. This downward beamis then split by two reflectors 307 and 306 which direct differentportions of the beam onto PDs 201 and 202, respectively.

Applications

The present invention has broad application to electronic devices withtouch sensitive screens, including small-size, mid-size and large-sizescreens. Such devices include inter alia computers, track pads forlaptops and computers, home entertainment systems, car entertainmentsystems, security systems, PDAs, cell phones, electronic games and toys,digital photo frames, digital musical instruments, e-book readers, TVsand GPS navigators.

Secondary Keyboard Display

Reference is made to FIG. 29, which is a simplified illustration of adual-display laptop, in accordance with an embodiment of the presentinvention. The laptop features two panels connected by a hinge. Theupper panel contains the primary laptop display 131. The lower panelcontains a touch-sensitive, secondary display 132 that is used as aninput device to the laptop. Thus, a keypad is rendered on secondarydisplay 132 and text is entered by the user tapping on the displayedkeys. Tap gestures are characterized by a brief contact, i.e.,touch-and-release, with the secondary display. Thus, tap gestures aredistinguishable from glide gestures which are characterized by prolongedcontact with the display during which the point of contact is translatedalong the display. Thus, in addition to text entry, the secondarydisplay controls a mouse cursor on the primary display when the userglides his finger on the secondary display.

According to an embodiment of the present invention the touch sensorused in conjunction with secondary display 132 is optical proximitysensor 512, as described hereinabove, situated along one edge of thesecondary display. Reference is made to FIG. 30, which is a simplifiedillustration of a portion of a dual-display laptop, in accordance withan embodiment of the present invention. FIG. 30 shows a bezel 331 alongthe top edge of the secondary display for housing the optical proximitysensor.

Reference is made to FIG. 31, which is a simplified illustration of aPC, in accordance with an embodiment of the present invention. FIG. 31shows a PC having a display 131, keyboard 133 and two trackpads 134, inaccordance with an embodiment of the present invention.

Reference is made to FIG. 32, which is a simplified illustration ofkeyboard 133 of the PC of FIG. 31, in accordance with an embodiment ofthe present invention. The keyboard has four embedded optical proximitysensors 513-516. Optical proximity sensors 513, 515 and 516 are placedalong the left, right and bottom edges of keyboard 133 facing away fromthe keyboard to detect hand and finger gestures in the airspacesurrounding the keyboard. These gestures serve as inputs to thecomputer, e.g., to control a mouse pointer or to enlarge or rotate animage on the display. Optical proximity sensor 514 is along the top edgeof keyboard 133 and faces the keyboard. It is used to detect glidegestures along the surface of the keys as inputs to the computer, e.g.,to control a mouse pointer or to enlarge or rotate an image on thedisplay. The keyboard's large size relative to traditional trackpadsenables dividing the keyboard surface into two trackpad sections. Theleft half of keyboard 133 serves as an absolute position trackpad. Thismeans that every location on this half of the keyboard is mapped to acorresponding location on the screen. Before a glide gesture isperformed, the mouse cursor is at some initial location on the screen.When a glide gesture is performed on the left half of the keyboard themouse cursor is suddenly moved to the corresponding location on thedisplay. For example, when the mouse cursor is at the upper right cornerof the display and the user begins a glide gesture in the lower leftcorner of the keyboard, the mouse cursor begins its correspondingmovement from the lower leftover of the screen. This spares the user theeffort of having to perform a long mouse gesture to move the cursoracross the screen. The right half of keyboard 133 serves as arelative-position trackpad meaning that when a glide gesture is detectedin this half of the keyboard the mouse cursor is translated from itsinitial screen location according to the relative movement of the glidegesture. Thus, the user can perform an initial slide gesture in the lefthalf of the keyboard to place the mouse cursor in a desired area of thescreen and then apply a glide gesture in the right half of the keyboardto move the cursor.

Reference is made to FIG. 33, which is a simplified illustration of a PCtrackpad 134, in accordance with an embodiment of the present invention.Trackpad 134 is a transparent slab of acrylic slightly tilted toward theuser. Optical proximity sensor 517 along the top edge of the trackpadtracks the user's gestures on the slab. Because no electronics areneeded on the trackpad outside the optical sensor, trackpad 134 is madeof entirely clear, transparent acrylic or glass.

Reference is made to FIG. 34, which is a simplified illustration oftransparent PC keyboard 135, in accordance with an embodiment of thepresent invention. Reference is also made to FIG. 35, which is a sideperspective view of transparent keyboard 135 of FIG. 34, in accordancewith an embodiment of the present invention. Similar to trackpad 134 ofFIG. 33, keyboard 135 is enabled by an optical proximity sensor alongits upper edge and a transparent slab of acrylic. The transparentacrylic slab has the keyboard characters etched inside it such that,when visible light is projected into the acrylic slab, the light isreflected by the etchings making the letters visible. When this light isturned off, the etchings are not visible and the keyboard appears as anempty transparent slab. Thus in keyboard mode the visible light isturned and in mouse or sweep-gesture input mode the visible light isturned off. The visible light source is mounted together with theoptical proximity sensor along the upper edge of the acrylic slab.

Reference is made to FIG. 36, which is a simplified illustration of asecondary display that provides keyboard and GUI functionality, inaccordance with an embodiment of the present invention. FIG. 36 shows akeyboard having a touch sensitive display. The keyboard characters arerendered by the display. However, an application can also render otherUI controls to indicate what gestures to perform on the keyboarddisplay. In FIG. 36 two slider wheels 136 and two slider bars 137 arerendered indicating available rotation gestures and slide gestures tothe user.

Reference is made to FIG. 37, which is a simplified illustration of alaptop keyboard, in accordance with an embodiment of the presentinvention. Reference is also made to FIG. 38, which is a simplifiedcross-section of the laptop keyboard of FIG. 37, in accordance with anembodiment of the present invention. FIG. 37 shows the laptop of FIGS.29 and 30, except that in FIG. 37 secondary display 132 uses light beams432 that cross above the display between emitter 101 and receiver 201placed along opposite edges of display 132. Light guides 332 provide abezel that extends above display 132 to project light beams 432 over andacross the display. In the embodiment of FIGS. 37 and 38 the cavityabove the display formed by the surrounding bezel is filled with clearliquid 139. The light beams from emitter 101 to receiver 201 passthrough clear liquid 139. Above liquid layer 139 a thin, transparent,elastic plastic film 141 is placed. The underlying secondary display 132is viewable through liquid 139 and plastic film 141. When the userpresses elastic plastic film 141, for example to select a keyboardcharacter displayed on secondary display 132, his finger causes animpression in liquid 139 that disrupts light beams 432 underneath thefinger's location. The liquid and elastic also provide the user with atactile feel when he presses this malleable layer above secondarydisplay 132. An optional haptic generator connected to plastic film 141or liquid 139 provides additional haptic feedback. In order that theuser's finger impression block a sufficient amount of the beams suchthat a touch causes a substantial reduction in detected light, light isonly transmitted through a thin upper layer of liquid 139 near the topof the bezel. This is achieved by the light blockers 140 that preventlight beams 432 from entering liquid 139 near the surface of display132. In other embodiments, instead of filling the cavity with a liquid,the cavity is filled with a transparent gel or elastic gelatinous solidmaterial.

Vertical Toolbar Approach Gestures

The Windows 8 operating system from Microsoft Corporation features avertical toolbar known as the charms that is accessed by swiping fromthe right edge of a touchscreen, or pointing the cursor at hotspots inthe right corners of a screen. WINDOWS® is a registered trademark ofMicrosoft Corporation. The charms toolbar provides access to system andapp-related functions, such as search, sharing, device management,settings, and a Start button. Swiping from the left edge of thetouchscreen primary display or clicking in the top-left corner of theprimary display allows one to switch between apps and the Desktop. Inorder to make these sweep gestures convenient for users, many computerssupport sweep gestures that begin in a border outside the active displayarea. According to an embodiment of the present invention an alternativegesture is provided for the same functions as sweeping from an edge ofthe primary display. This gesture is performed by placing a hand in theairspace beyond an edge of the primary display and moving the handtowards the edge. If the gesture is continued until the hand touches theprimary display housing, the hand would touch the thickness of thedisplay. I.e., the hand would touch the edge of the housing connectingthe front of the display to the rear of the display. However, the handneed not reach the display; the detection of an object approaching thedisplay from the side is recognized as the gesture.

Reference is made to FIG. 39, which is a simplified illustration of a PCwith proximity sensors for detecting wave gestures that approach a sideedge of the display, in accordance with an embodiment of the presentinvention. FIG. 39 shows PC display 131 having optical proximity sensor512 arranged along the outer left edge of the display housing fordetecting this approach gesture in the airspace beyond the edges of thedisplay. In order to make these sweep gestures convenient for users,many prior art computers support sweep gestures that begin in a borderoutside the active display area. The approach gesture according to thepresent invention enables maximizing the active display area as noborder area around the display is required for this gesture. The gestureaccording to the present invention also does not require touching theactive display area and thereby avoids smudges on the display resultingfrom the prior art sweep gestures that draw a finger into the activedisplay area.

Using Secondary Display for Key Press and Mouse Gestures

As mentioned hereinabove, embodiments of the present invention provide asecondary display that is touch sensitive and is used for both keyboardinput and mouse input. The present invention provides several methods todistinguish between keyboard key presses and mouse gestures.

In a first embodiment tap gestures are associated with keyboard keypresses and glide gestures are associated with mouse gestures that movethe mouse cursor. In addition, three mouse click gestures are providedthat are distinct from keyboard key presses: single-click, double-clickand right-click.

A right-click gesture according to the present invention is a prolongedtouch that remains in one location, as opposed to a tap gesture which isa quick touch-and-release.

A double-click gesture activates an item located at the location of themouse cursor. According to the present invention a double-click gestureis distinguished from a key press in that a double-click gesturenecessarily follows another mouse gesture, i.e., it is the first tapafter a mouse gesture. Thus, after a mouse translation gesture isperformed, the next tap gesture may be either the first half of adouble-click gesture or a key press gesture. The system disambiguatesthis tap based on what follows the tap. If this tap is quickly followedby a second tap at approximately the same location as the first tap,both taps are treated as a double-tap gesture; if the first tap is notquickly followed by a second tap at approximately the same location asthe first tap, the first tap is associated with a keyboard key press.Thus, with respect to this first tap following a mouse glide operation,the system does not immediately enter the character associated with thecorresponding key press gesture. Rather, the system waits until itdetermines that the tap is in fact an intended key press and not thebeginning of a double-click gesture. However, all subsequent taps areunambiguously determined to be keyboard key presses until another mouseglide gesture is performed. In addition, a double-click does notimmediately follow a double-click gesture, so even when a double-clickis executed, the third tap is definitely a key press gesture. Therefore,the delay in presenting the character on the screen only occurs onlywith regard to the first tap gesture following a mouse operation such asa glide or right-click, but not for any other key presses.

A single-click is used to perform a mouse drag operation. According toan embodiment of the invention, a mouse drag operation is only performedwith respect to a second mouse glide gesture that quickly follows afirst mouse glide gesture. Thus a first glide gesture only moves themouse cursor on the screen. If the user then lifts his finger and then,within a short amount of time, replaces his finger on the screen andperforms a second glide gesture, the second glide gesture is interpretedto be a drag gesture. The short amount of time is configured based onobserved user behavior, but in some cases may be 1 or 2 seconds. Inorder to perform a second operation of moving the mouse cursor without adrag operation there must be a pause—longer than the configured shortamount of time—between the first and second glide gestures.

In an alternative embodiment the distinguishing factor between keypresses and mouse gestures is the number of fingers performing thegesture. Thus, single-finger gestures are keyboard key presses andtwo-finger gestures are mouse gestures. Gestures performed by more thetwo fingers are also mouse gestures.

A system according to the teachings of the present invention thatdetects a touch based on shadowed light pulses determines the number offingers performing a gesture based on the size of the shadowed area. Alarger area indicates that multiple fingers are being used. Similarly, asystem according to the teachings of the present invention that detectsa touch based on reflected light pulses determines the number of fingersperforming a gesture based on the number of different emitter-receiverchannels that detect reflections. A larger number of channels,corresponding to more touch locations, indicates that a large surfacearea of the screen is being touched, i.e., multiple fingers are beingused.

In certain embodiments an array of up/down translatable buttons issituated on top of the secondary display to provide a traditionalpush-button user experience when entering data through the keyboard.Reference is made to FIG. 40, which is a simplified illustration ofthree views of an exemplary four-button keypad chassis, situated over avirtual keypad portion of a touch panel, in accordance with anembodiment of the present invention. FIG. 40 shows keys 10 in removablechassis 12. Touch panel 14 is situated beneath chassis 12. Emitters andreceivers 16 are shown as part of touch panel 14. Emitters and receivers16 are placed beneath surface 14 but are shown above the screen in FIG.40 in order to clearly indicate touch detection light beams 20.

Reference is made to FIG. 41, which is a simplified illustration of across-section A-A of an exemplary four-button keypad chassis, situatedover a virtual keypad portion of a touch panel, in accordance with anembodiment of the present invention. FIG. 41 shows keys 10 in removablechassis 12. Touch panel 14 is situated beneath chassis 12. Emitter andreceiver lenses 22 are shown with touch detection light beam 20 abovethe surface of touch panel 14.

Reference is made to FIGS. 42(a)-(c), which are simplified illustrationsof a spring-resilient key that is released and depressed, in accordancewith an embodiment of the present invention. FIG. 42(a) shows key 10 ina portion of removable chassis 12. Touch panel 14 is situated beneathchassis 12. Emitter and receiver lenses 22 are shown with touchdetection light beams 20 above the surface of touch panel 14.

FIG. 42(b) is a cutaway of button 10 showing spring mechanism 24 formaintaining button 10 upward in chassis 12 and above light beam 20. FIG.42(c) is a cutaway of button 10 showing spring mechanism 24 beingcompressed by downward pressure exerted by a user pressing button 10. Inthis case, the bottom of button 10 is lowered to block light beam 20.When the user releases this downward pressure, spring 24 returns button10 to its position in FIG. 42(b).

Reference is made to FIGS. 43(a) and (b), which are simplifiedillustrations of a cross-section of a button made of an elastic,resilient material such as rubber, in accordance with an embodiment ofthe present invention. FIG. 43(a) is a cutaway of elastic button 10upward in chassis 12 and above light beam 20 projected through emitterand receiver lenses 22 over and across touch panel 14.

FIG. 43(b) is a cutaway showing button 10 being depressed by downwardpressure exerted by a user pressing button 10. In this case, the bottomof button 10 is lowered to block light beam 20. When the user releaseshis downward pressure button 10 returns to its position in FIG. 43(a)due to its resilient and elastic properties.

Reference is made to FIGS. 44(a)-(d), which are simplified illustrationsof an alternative button configuration, in accordance with an embodimentof the present invention. Button 10 of FIG. 44 has two intersectingcavities 30 through its trunk that allows light beams 20 to pass. Whenbutton 10 is depressed, the cavity is lowered and a solid portion of thetrunk blocks the light beams.

FIG. 44(a) is a 3-D view of the button. FIG. 44(b) is a top view of thebutton, and FIG. 44(c) is a side view of the button. FIG. 44(d) is across section along line M-M of the button. Button 10 of FIG. 44 ismaintained in its upward position using either the spring loadedembodiment of FIG. 42 or the resilient material embodiment of FIG. 43.

According to the present invention, these buttons are made of FiberOptic Faceplates. A Fiber Optic Faceplate (FOFP) is a coherent fiberoptic plate that precisely transmits an image from its input surface toits output surface. Thus, the displayed image underneath each key istransmitted by the FOFP to the upper surface of the key and appears tothe user as if the image is on the upper surface of the key.

However, the present invention provides an air gap between each FOFP keyand the display in order to enable lowering the key when the key ispressed. In addition, light beams are projected underneath the keys suchthat a lowered key blocks beams indicating which key is being depressed,as explained hereinabove, and in U.S. patent application Ser. No.13/602,217, entitled LIGHT ACTUATOR FOR MOVABLE BUTTONS ON A KEYPAD, andfiled on Sep. 3, 2012, the contents of which are incorporated herein byreference. This air gap causes the displayed image to be out of focus atthe FOFP input surface. In some embodiments the height of the air gap is1.5 mm.

In order to correct this problem the present invention provides aplurality of micro lens arrays that reproduce an object—in this case thedisplay screen, over a distance of a few millimeters. Reference is madeto FIG. 45, which is a simplified illustration of an arrangement ofmicro lens arrays between a keyboard display and a fiber optic faceplate key in accordance with an embodiment of the present invention.FIG. 45 shows four micro lens arrays 51-54 axially aligned in asymmetric fashion between secondary display 56 and the FOFP inputsurface 57 of an FOFP button. In each optical channel, the first andsecond micro lens arrays 51 and 52 produce a de-magnified, invertedimage of the respective part of the display screen in the intermediateimage plane. A reversed group of the same micro lenses, 53 and 54,relays the intermediate image onto FOFP input surface 57. Since eachpartial image has unity magnification, a total image of all partialimages results in a complete reconstruction of the final image. The sizeand possible overlap of adjacent partial images is controlled byaperture mask 55 which lies in the center of axial symmetry.

In an exemplary embodiment the lens arrays are polycarbonate, 0.1 mmthick; each lenslet is 0.2 mm square; the aperture mask has 0.076 mmsquare holes; and object to image distance is 4.7 mm.

Reference is made to FIG. 46, which is a simplified illustration of akey or button 59, in accordance with an embodiment of the presentinvention. The micro lens arrays 51-54 are connected to FOFP 58 and theymove up and down together. When the button is in a resting, non-actuatedposition, the distance d1 between the micro lens arrays and the displaysurface equals the distance d2 between the micro lens arrays and theFOFP. This ensures that the image on the display is sharply reproducedon the FOFP. When the button is lowered, by the user pressing on thebutton, the distance d1 is reduced causing the image on FOFP 58 to beout of focus. However, this is not problem for the user because hisfinger is covering the output surface of FOFP 58 so the out-of-focusimage is not viewable. When the user removes his finger from the key,the key has returned to its resting position and FOFP 58 is again infocus.

Bar Code for Proximity Sensor

Embodiments of the present invention provide a low-cost proximity sensorfor detecting directional glide gestures along a linear UI control. Forexample, a volume control is realized as a narrow window along an edgeof a device. A slide in one direction along the window increases thevolume and a slide in the opposite direction along the window decreasesthe volume.

Reference is made to FIG. 47, which is a simplified illustration of aslider control, in accordance with an embodiment of the presentinvention. FIG. 47 shows a side cutaway view of a slider windowoperative to detect a directional glide. The window includes twoadjacent light guides: upper light guide 333 is coupled to emitter 101and lower light guide 334 is coupled to a detector 201. Between the twolight guides there is a staggered series of opaque or reflectivelight-blocking elements 335 that do not allow light to pass between thetwo light guides. The spaces between these opaque or reflective elementsare of different sizes. Light 433 from emitter 101 enters the lightguide 333 where it is contained due to total internal reflection (TIR).When a finger touches the light guide 333 it scatters the light andfrustrates the TIR such that a large portion 434 of the FTIR light isscattered directly into lower light guide 334 and toward detector 201.However, the light can only pass into light guide 334 through the spacesbetween opaque or reflective elements 335. Therefore, when the finger issituated opposite an area where the spaces between opaque or reflectiveelements 335 are large, much light will pass into the light guide 334and arrive at PD 201. Whereas, when the finger is situated opposite anarea where the spaces between opaque or reflective elements 335 aresmall, less light will pass into the light guide 334 and arrive at PD201. As the finger glides along the light guide 333 it passes acrosssections having different sized gaps between elements 335. As a result,the movement of the finger can be inferred from the pattern of lightdetections at PD 201 over time.

Reference is made to FIG. 48, which is a simplified illustration ofvarious detection patterns of gestures using the slider control of FIG.47, in accordance with an embodiment of the present invention. FIG. 48shows four different detection patterns. Each graph shows samples oflight detection at the PD over time. The x-axis represents time and they-axis represents the amount of light detected. Thus the direction ofmovement along the light guide is indicated by the pattern ofdetections: in this example, an ascending pattern corresponds to slidingright whereas a descending pattern indicates movement in the oppositedirection. The speed of the movement is indicated by the rate of changein the detections: faster rates of change correspond to faster movement.

Reference is made to FIG. 49, which is a simplified illustration of analternative slider control, in accordance with an embodiment of thepresent invention. FIG. 49 shows an embodiment wherein emitter 101projects light beams 336 directly onto finger 922 touching the uppersurface of light guide 333, on which there is a pattern of opaque orreflective elements 335 that prevent reflected light from entering lightguide 333. Therefore different amounts of light 336 reflected off finger924 enter light guide 333 and are detected by detector 201, depending onthe pattern of light blocking elements near the finger.

Recreational Applications for Optical Proximity Sensor

One application for the present invention is interactive glasses such asGOOGLE® GLASS®. GOOGLE and GOOGLE GLASS are registered trademarks ofGoogle Inc. of Mountain View, Calif. Interactive glasses include ahead-up display in one or both glasses lenses. Interactive glasses aretypically supported by pads on the bridge of the nose and by temple arms(sides) placed over the ears. In some interactive glasses the templearms include touch sensors that enable user commands to be communicatedby tap gestures or sliding gestures on the temple arms.

Thus, in some embodiments of the invention, the optical proximity sensorof the present invention is embedded in the temple arms of interactiveglasses to enable user input gestures within a range of distances apartfrom the temple arms. This enables a 2D airspace opposite the temple armfor in-air user input gestures. Multiple rows of optical proximitysensors stacked along the temple arms provide a 3D sensor. In otherembodiments, a first optical proximity sensor faces away from the user'stemple and a second optical proximity sensor faces skyward, to detectgestures to the side of, and above, the user's head.

Another application is a sensor worn as a wristwatch. In variouswrist-worn embodiments of the present invention, the optical proximitysensor is a one-dimensional row of diodes; a two dimensional grid ofdiodes; a two-dimensional snowflake pattern of diodes; two or moreone-dimensional rows of diodes along two or more edges of the worn item.In one exemplary embodiment the optical proximity sensors are embeddedin a wristwatch and project light beams upward through the watch face orits surrounding bezel. The user issues commands to the watch byperforming hover gestures such as waving a hand over the watch.Alternatively, when the user rotates the wrist wearing the watch, hechanges the amount of reflected light detected in the optical proximitysensor and this is translated into a command. For example, the opticalproximity sensor communicates over BLUETOOTH® with the user's cellphone, and a rotation of the wrist is a command to answer an incomingcall. BLUETOOTH is a trademark of Bluetooth SIG, Inc. A slower rotationgesture is a command to raise or lower the cell phone headset volume.

The optical proximity sensor also distinguishes between a finger gesturethat returns localized reflections and a gesture made by a flat palmthat returns reflections across a large portion of the optical proximitysensor. This enables responding to only one type of gesture (finger orpalm).

Moreover, the optical proximity sensor of the present inventiondistinguishes between a flat palm above the sensor and a tilted palmabove the sensor. When the palm is tilted over the optical proximitysensor, the reflections are not uniform—according to the variousdistances between portions of the tilted palm and the sensor. Bycontrast, a flat, even palm perpendicular to the sensor emitter beamsreflects all of the sensor beams in the same way.

Another application is a bracelet with the detection plane aimed belowthe user's palm to detect curled fingers. The four fingers on a handrepresent four bit positions and the user forms four-bit words bycurling his fingers, where a curled finger is a bit value of ‘1’ and aprone finger is a bit value of ‘0’. These four-bit values are detectedby the optical proximity sensor and translated into commands.

An additional application uses two such bracelets, one on each wrist.The user creates 8-bit words by curling combinations of four fingers oneach hand. This provides 256 unique combinations whereby a subset ofthese combinations is assigned to every letter of the alphabet. The usertypes text by curling his fingers to form the various 8-bit lettercombinations. This provides an alternative method to input text withouta keypad.

Another application is a protective casing for a mobile phone. Thisapplication is explained in detail in U.S. patent application Ser. No.13/775,269, for REMOVABLE PROTECTIVE COVER WITH EMBEDDED PROXIMITYSENSORS, which is hereby incorporated in its entirety by reference. Anapplication for a game accessory based on this protective casing isdescribed with reference to FIGS. 50-53.

The accessory is a slingshot, which can be used in many games, interalia, ANGRY BIRDS®, published by Rovio Entertainment Ltd., of Espoo,Finland, and owner of the ANGRY BIRDS trademark. In this video game,players catapult birds as projectiles using a slingshot or catapult. Theplayer draws back the catapult to a desired extent to provide power forthe projectile birds by sliding his or her finger along the screen.Lifting the finger from the screen releases the catapult, hurling thebird through the air at a target. The angle at which the catapult isdrawn back determines the direction in which the bird is hurled. Thedegree to which the catapult is draw back determines the force of theprojectile.

The present accessory enables the player to draw back an actual elasticslingshot attached to an edge of the phone casing. Reference is made toFIG. 36 in U.S. patent application Ser. No. 13/775,269 showing anexample of a phone cover with embedded proximity sensors. FIG. 34 inU.S. patent application Ser. No. 13/775,269 illustrates a phone in thecover of FIG. 36. FIG. 39 in U.S. patent application Ser. No. 13/775,269illustrates a layout of components on a PCB in the phone cover of FIG.36.

Embodiments of the present invention incorporate optical proximitysensor 512, described hereinabove, into a protective phone cover.Different embodiments will have the optical proximity sensor along 1-4edges of the cover.

Reference is made to FIGS. 50-53, which are simplified illustrations ofa game accessory in accordance with an embodiment of the presentinvention. Thus a PCB 976 is shown having an array of alternatingemitters 101 and detectors 201 along a bottom edge of the casing.Attached to the two corners at the bottom edge of the casing are elasticbands 933 tied to slingshot pad 934. This array of emitters anddetectors identifies how the player draws back slingshot pad 934.

FIGS. 51-53 show three different extensions 935 of slingshot pad 934. Ineach figure, the x and y offsets detected by the one-dimensional arrayalong the bottom edge are indicated by dashed arrows.

Several different methods are used to determine the extent and angle towhich the slingshot is drawn back, e.g., as indicated by extension arrow935 in FIGS. 51-53. In a first embodiment, elastic band 933 issubstantially thinner than slingshot pad 934. Therefore, the amount oflight reflected by elastic band 933 is substantially less than what isreflected by slingshot pad 934 to enable the system to track theposition of slingshot pad 934. In a similar vein, even if slingshot pad934 is not present, the two fingers with which a user pinches elasticband 933 in order to draw it back are much larger than the elastic band,and therefore, the user's two fingers can be tracked. In yet anotherembodiment the elastic band 933 is situated at a different height thanthe light beams projected by the proximity detector. Thus, the elasticband 933 is not detected by the detector. However, the larger slingshotpad and/or the user's fingers drawing back the elastic band, extendthrough the plane of light beams projected by the detector and aretherefore detected. In yet another embodiment, the detector is formed bytwo, stacked arrays of emitters, detectors and lenses. The combinedheight of the two arrays is greater than the width of elastic bands 933.Therefore, elastic band 933 will not generate the same detection signalsin both arrays. However, the combined height of the two arrays is lessthan the width of slingshot pad 934 and the user's two fingers andtherefore these items generate similar detection signals in both arrays.In yet another embodiment, elastic band 933 does generate a significantdetectable signal. In this case a signal pattern is generated across theentire detector array corresponding to the different distances betweeneach section of the drawn-back elastic band and the detector array. Thefarthest distance is at the location of the slingshot pad or the user'sfingers. Thus, by mapping the detection signals, a triangular shape willbe mapped corresponding to the shape of the drawn-back slingshot.

In another embodiment an optical proximity sensor 512 is attached via ahinge to an edge of a display. In some embodiments multiple opticalproximity sensors 512 are attached to multiple edges of the display.Reference is made to FIG. 54, which is a simplified illustration of adisplay surrounded by four proximity sensor bars connected to thedisplay by rotating hinges, in accordance with an embodiment of thepresent invention. FIG. 54 shows display 911 surrounded on four sides byoptical proximity sensors 512. Each touch sensor bar is attached viahinges 950 to the display housing. As explained hereinabove, eachoptical proximity sensor 512 projects a 2D detection plane. Thus, hinges950 enable aiming the 2D detection plane for each touch sensor bar 510at an angle to display 911. When rotated to aim the 2D detection planeat an angle above display 911, touch sensor bar 510 provides hoverdetection. When rotated to aim the 2D detection plane parallel to thescreen surface, optical proximity sensor 512 provides touch detection.Moreover, when one or more optical proximity sensor 512 is rotated toaim the 2D detection plane parallel to the screen surface, and a secondone or more array is rotated to aim the 2D detection plane at an angleabove the screen, both touch detection and hover detection are provided.In FIG. 54, all four optical proximity sensors 512 are rotated to aimtheir respective detection planes at respective angles above and acrossdisplay 911. The four intersecting detection planes in this case providea 3D detection volume above screen 911.

Another recreational application enables cloud gaming applications to bedisplayed on multiple handsets as a multi-panel display. A user arrangesthe handsets as tiles to form a large, rectangular multi-panel display.The game server identifies where each handset display is located withinthe multi-panel display. The game server streams respective portions ofthe game GUI to each handset such that the full screen game GUI isdistributed across the handsets. In some embodiments, each handset inthe multi-panel display has an optical proximity sensor 512 as describedhereinabove.

Reference is made to FIG. 55, which is a simplified illustration of ahandheld electronic game device 994 having communicator 703 forcommunicating with internet game server 991, in accordance with anembodiment of the present invention. Display 100 in device 994 renders aportion of a game user interface (UI) received by communicator 703 fromgame server 991. Sensor 512 detects a second game device placed nearbyand is connected to communicator 703 to send the detection informationto the game server. In accordance with an embodiment of the presentinvention, sensor 512 may be similar to optical proximity sensor 512discussed above.

Reference is made to FIG. 56, which is a simplified illustration of aninternet game rendered on a handset, in accordance with an embodiment ofthe present invention. FIG. 56 shows an internet game server 991 incommunication with handset 994. The game logic is processed by server991 which sends the game GUI to handset 994. The game's GUI is renderedon a single screen. The area surrounding all four edges of handset 994is used for user gestures to control the game, as described hereinabove.These gestures are detected by proximity sensors 512 along the edges ofthe handset, or along the edges of a protective cover used together withthe handset, which form top and bottom detection zones 998 and left andright detection zones 999.

Reference is made to FIG. 57, which is a simplified illustration of twohandsets being used together to render an internet game, in accordancewith an embodiment of the present invention. FIG. 57 shows an internetgame server 991 in communication with two handsets 994 and 995, viarespective communication processors 983 and 984. The two handsets arealigned along a common edge, namely the long lower edge of handset 994is aligned with the long upper edge of handset 995. As such, these edgesbetween the two handsets are not usable for detecting gestures outsidethe handsets. However, these edges detect each other. For example,detection zone 998 along the upper edge of handset 995 detects handset994. Thus, handset 995 communicates to server 991 that the entire longupper edge above 995 is occupied by a proximal object. Similarly,handset 994 communicates to server 991 that the entire long bottom edgeof handset 994 is occupied by a proximal object. Based on thisinformation, server 991 determines that the proximal object detected byeach handset is the neighboring handset. Accordingly, server 991 sendsthe upper half of the game GUI to handset 994 and the lower half of thegame GUI to handset 995. Furthermore, based on the screen orientation,e.g., the location of the detecting edge in relation to pixel (0,0) onthe detecting handset's display, server 991 determines whether to rotateone or both of the half-GUI images in order that they will be renderedproperly on their target handsets. This ensures continuity from onehandset display to the next, so that together the two handsets display acontiguous GUI.

Reference is made to FIG. 58, which is a simplified illustration of atwo-panel display for an internet game, the display being made up of twohandsets, in accordance with an embodiment of the present invention.FIG. 58 shows an internet game rendered on two handsets 994 and 995,i.e., the game GUI is rendered on two screens: the upper half of the GUIis rendered on handset 994, and the lower half of the GUI is rendered onhandset 995. Because the number of devices communicating with theInternet game server in this instance of the current game is two, thegame server divides the GUI into two portions. The number of portionsthe game server divides the GUI into, is according to the number ofdevices communicating with the Internet game server in a particularinstance the game.

As explained above with reference to FIG. 57, the edges between the twohandsets are not usable for detecting gestures outside the handsets.However, the remaining three exposed edges of each handset are usablefor detecting user input gestures in the open space outside thehandsets. The exposed handset edges form the periphery of themulti-panel display and are used for detecting user gestures in the openspace outside the multi-panel display. The handset alignment informationdescribed above, whereby server 991 determines how the two handsets areoriented in relation to each other and what part of the GUI is renderedon each handset, also enables the game server to map a gesture thatspans the open space of two handsets as a single gesture. For example,if the user performs a glide gesture by gliding his finger upwardsopposite the right edge of the multi-panel display, as illustrated byarrow 939, the gesture is first detected at zone 999 of handset 995 andthen at zone 998 of handset 994. Each handset sends its proximity zonedetection information to server 991. Server 991 stores informationrelating to the arrangement of the panels. Based on the handsetalignment information, server 991 combines these two glide detections toform one long upward glide gesture opposite the right edge of themulti-panel display.

Reference is made to FIG. 59, which is a simplified illustration of afour-panel display for an internet game, the display being made up offour handsets, in accordance with an embodiment of the presentinvention. FIG. 59 shows an internet game on four handsets 994-997. Thegame GUI is rendered on four screens, each screen displaying arespective quarter of the GUI. As explained hereinabove, each of theedges between neighboring handsets detects a neighboring handset. Thusin a four-handset arrangement each handset detects two neighbors. Bysending this information to the server, the server maps how the fourhandsets are arranged and sends an appropriate quarter of the GUI toeach handset so that the four handsets together display a contiguousGUI. As mentioned, it may be necessary that the server rotate some ofthe images sent to the different handsets.

In some embodiments, the detector along each device edge is analternating series of light emitters and light detectors, whereby thedetectors detect light reflected by an object, such as a neighboringdevice. However, in some embodiments, an activation pattern of lightemitters along a device edge is detected by the opposite array ofdetectors on its neighboring device. This is an alternative method fordetecting a neighboring active device. It also enables determining therelative orientation of the two devices. For example, if the emittersnear the top of the display are activated in an activation patterndifferent than those activated near the bottom of the display, theneighboring device determines where the top of the neighboring device issituated based on the different detections at its light detectors.

As explained hereinabove, the remaining exposed handset edges form theperiphery of the multi-panel display and are used for detecting usergestures in the open space outside the multi-panel display. Thealignment information described above, based on the handset edgessituated between handsets, also enables the game server to map a gesturethat spans the open space opposite two handsets, indicated as zones 998and 999 in FIG. 59, as a single gesture.

In some embodiments each device includes a dedicated emitter and sensorthat employ an automated process of negotiation that dynamically sets upa communications channel between the two devices. In informationtechnology, telecommunications, and related fields, this process isknown as handshaking. Thus, for example, a first device's emittergenerates a handshake signal that is detected at the sensor on theneighboring device. The neighboring device emitter generates areciprocal handshake signal that is detected at the first device'ssensor. Light emitters and light sensors are capable of handshaking.However, other types of emitter/sensor are also within the scope of theinvention, inter alia, RFID. Thus, regardless of the technology used:(a) the neighboring devices detect each other; (b) each devicecommunicate this detection to the Internet game server; and (c) based onthis information, the Internet game server sends respective portions ofthe game GUI to each device.

Reference is made to FIG. 60, which is a simplified illustration of aconfiguration of four game devices, as shown in FIG. 59, whereby thegame GUI is distributed among the four displays 142-145 according toeach display's relative position and orientation detected by sensors 518and communicated to game server 991, in accordance with an embodiment ofthe present invention. Thus, FIG. 60 illustrates an internet gamingsystem featuring internet game server 991 and a number of game devices,each of which is a handheld electronic game device in communication withthe game server via individual communicators 703 embedded in eachdevice. Each device has a respective display 142-145 for rendering arespective portion of a game user interface (UI) received bycommunicator 703 from game server 991. Each device also has a respectivesensor 518, connected to communicator 703, for detecting presence of aneighboring game device. Game server 991 determines the size of eachrespective portion of the game UI based on the number of game devices.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made to thespecific exemplary embodiments without departing from the broader spiritand scope of the invention. Accordingly, the specification and drawingsare to be regarded in an illustrative rather than a restrictive sense.

1-30. (canceled)
 31. A proximity sensor, comprising: a housing; an arrayof lenses mounted in said housing; an array of alternating lightemitters and light detectors mounted in said housing, each detectorbeing positioned along the image plane of a respective one of saidlenses so as to receive maximum light intensity when light enters thelens at a particular angle; an activating unit mounted in said housingand connected to said emitters and detectors, synchronouslyco-activating each emitter with at least one of said detectors, eachactivated emitter projecting light out of said housing along a detectionplane; and a processor receiving outputs from said detectorscorresponding to amounts of projected light reflected by an object inthe detection plane to said detectors, and calculating a two-dimensionallocation of the object in the detection plane based on the detectoroutputs and the particular angle.
 32. The proximity sensor of claim 31,wherein each detector is positioned along the image plane of arespective second one of said lenses to receive maximum intensity whenlight enters the second lens at a second particular angle, enabling saidprocessor to calculate the two-dimensional location of the object in thedetection plane based on the detector outputs and the second particularangle.
 33. The proximity sensor of claim 32, wherein the particularangle and the second particular angle for each lens are on separatesides of the lens's optical axis.
 34. The proximity sensor of claim 31,wherein each of said emitters is positioned such that the light itprojects out of said housing passes through a respective one of saidlenses.
 35. The proximity sensor of claim 31, wherein said array ofalternating light emitters and light detectors comprises an array ofdiodes mounted on a single PCB, and wherein no light transmissivematerial separates the diodes from said lenses.
 36. A car, comprisingthe proximity sensor of claim 31 mounted in the car body detectingobjects outside the car.